Nuclear fusion events in the sun provide the heat and light we experience on Earth. These processes emit large amounts of cosmic radiation, including X-rays, gamma rays, and charged particles, which can be damaging to all living creatures. A magnetic field that pushes charged particles to bounce from pole to pole, as well as an atmosphere that filters hazardous radiation, have kept life on Earth safe. However, when space flight, the scenario is different. Scientists are sending baker's yeast to the moon as part of NASA's Artemis 1 mission to investigate what happens in a cell when it travels in space.
Cosmic radiation can harm cell DNA, increasing the likelihood of neurological illnesses and deadly diseases like cancer in humans. Because the International Space Station (ISS) is positioned in one of Earth's two Van Allen radiation belts, astronauts are not too exposed. Microgravity, another stimulus that may profoundly modify cell physiology, is experienced by astronauts on the International Space Station. These environmental challenges get increasingly difficult as NASA plans to send people to the moon and, subsequently, Mars. The most popular method of protecting astronauts from the harmful effects of cosmic rays is to physically shelter them using cutting-edge materials.
Several studies reveal that hibernators are more resistant to large amounts of radiation, and some researchers have proposed using synthetic or induced torpor to safeguard people during space missions. Another strategy to safeguard life from cosmic rays is to investigate extremophile species, which can withstand extreme environmental pressures. Tardigrades, for example, are micro-animals that have demonstrated remarkable tolerance to a variety of stressors, including damaging radiation. This extraordinary toughness is due to a protein class known as tardigrade-specific proteins.
Under the leadership of molecular scientist Corey Nislow, I examine cosmic DNA damage stress using baker's yeast, Saccharomyces cerevisiae. We're taking part in NASA's Artemis 1 mission, in which our yeast cells will travel to the moon and return aboard the Orion spacecraft for 42 days. This collection comprises around 6,000 bar-coded yeast strains, each with one gene removed. If the deletion of a certain gene influences cell growth and replication, such strains would begin to lag when exposed to the environment in space.
My main endeavor at Nislow lab is to genetically modify yeast cells to produce tardigrade-specific proteins. We may next investigate how those proteins affect cell physiology and tolerance to environmental challenges, including radiation, in the hope that this knowledge will be useful when scientists attempt to create animals with these proteins. When the mission is done and we receive our samples, we may count the quantity of each strain using the barcodes to discover genes and gene pathways required for surviving damage caused by cosmic radiation.
Yeast has long been used as a "model organism" in DNA damage research, which means there is a wealth of knowledge about the processes that yeast uses to respond to DNA-damaging chemicals. The majority of yeast genes involved in DNA damage response have been thoroughly investigated. Despite variations in genetic complexity, the function of most genes involved in DNA replication and DNA damage response has remained so similar between the two that researching yeast may provide us with a wealth of knowledge about human cells' DNA damage response.
Furthermore, the simplicity of yeast cells in comparison to human cells (yeast contains 6,000 genes versus over 20,000 genes) allows us to make more reliable findings. In yeast experiments, the entire process of feeding the cells and arresting their development can be automated in a shoebox-sized electronic device, but growing human cells takes more space in the spaceship and significantly more intricate technology. Such research is critical for understanding how astronauts' bodies deal with long-term space journeys and developing appropriate responses. Once we've identified the genes that play critical roles in surviving cosmic radiation and microgravity, we'll be able to seek medications or therapies that can assist improve the cells' resilience to such challenges. We may then put them to the test in other animals (such as mice) before applying them to astronauts. This knowledge might also be valuable for cultivating plants on planets other than Earth.